Transcriptional repression by the Epstein-Barr virus EBNA3A protein tethered to DNA does not require RBP-Jkappa.
The Epstein-Barr virus (EBV) proteins EBNA1, EBNA2, EBNA3A, EBNA3C, LMP1 and EBNA-LP are essential for the in vitro immortalization of primary B lymphocytes by EBV. EBNA2 is a transcriptional activator of viral and cellular genes. Both EBNA3A and EBNA3C have been shown to specifically inhibit EBNA2-activated transcription by direct interaction with RBP-Jkappa, a cellular DNA-binding factor known to recruit EBNA2 to EBNA2-responsive genes. This interaction interferes with the binding of RBP-Jkappa to DNA in vitro, and this is probably the mechanism by which EBNA3A and EBNA3C repress EBNA2-activated transcription in vivo. EBNA3A and EBNA3C also directly repress transcription when tethered to a promoter via the DNA-binding domain of the yeast Gal4 protein. As RBP-Jkappa has been previously shown to be a repressor in mammalian cells, this repression could be due to the recruitment of RBP-Jkappa by Gal4-EBNA3A and 3C. In this study, we have precisely mapped the domain of EBNA3A involved in the interaction with RBP-Jkappa and we have shown that interaction with RBP-Jkappa is not required for the Gal4-EBNA3A-mediated repression. Furthermore, we have characterized in EBNA3A a domain of 143 amino acids which is necessary and sufficient for EBNA3A-dependent repression.
Bourillot
P Y
PY
Unité de Virologie Humaine, ENS-INSERM U412, Ecole Normale Supérieure de Lyon, France.
Waltzer
L
L
Sergeant
A
A
Manet
E
E
D004268:DNA-Binding Proteins / Q000378:metabolism*; D019309:Epstein-Barr Virus Nuclear Antigens / Q000096:biosynthesis / Q000378:metabolism*; D017930:Genes, Reporter; D006367:HeLa Cells; D004854:Herpesvirus 4, Human / Q000502:physiology*; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
D004268:DNA-Binding Proteins; D019309:Epstein-Barr Virus Nuclear Antigens; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D009687:Nuclear Proteins; C497570:RBPJ protein, human; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators